Control Conditions for the Second Class Crack of Concrete Based on Different Modulus Theory

Many engineering materials exhibit different elastic properties under the extension and compression. Among these materials, the concrete is a typical material which has different extension modulus and compression modulus. Based on different modulus theory, mechanical analysis was performed in this paper for reinforced concrete beams, stress formula was deduced, and the corresponding formula was applied to concrete structures with second-class crack control, which has improved the original crack control conditions in the code for design of concrete structures in China based on the classical modulus theory.